During the last part of lecture 4, we learned a little more about the design of the World Trade Center and what factors lead to the collapse of it. Knowing the layout of the building, it seems obvious as to the reason why the buildings fell. The thing that confuses me with the design of the floor joints. Based of the diagram in the lecture, why wasn't there a backup or at least something better designed to withstand shrinking or expanding metal? The only thing that we can see from it is just 2 small clips. On Aloha Airlines Flight 243, seeing the middle compartment of the plane gone it's amazing that no other part of the plane fell off. Both this plane incident, and the incident at the Mianus river could have easily been dealt if proper inspection was constant throughout.